V2G has huge potential to help balance the grid by leveraging the latent capacity of idle battery storage, but do the numbers stack up for Australian fleet owners?
Electrification of "Last Mile" Delivery Trucks
There's lots of interest in modelling the impacts of electric vehicle charging with customers in Australasia and Europe at the moment, which means we're often looking at really interesting simulations in the software
In this post I explore the impact of a supermarket electrifying a small fleet of refrigerated "last mile" delivery trucks.
These vehicles are often in the 4 tonne range, not much more than a large van really, and represent a very sizeable chunk of the commercial fleet around the world. In Europe there are many 1000s of eTrucks like this already on the road.
The concern from the supermarket operator in this case is that they won't have a sufficiently large grid connection to support the fleet electrification program.
The simulation looks at three scenarios:
Scenario 1: A base case with no fleet electrification, so just includes the supermarket's existing electricity needs with the existing energy supply arrangements for energy commodity and network
Scenario 2: The addition of 5 "last mile" electric delivery trucks with the same energy supply setup
Scenario 3: Same as scenario 2 but with the customer instead procuring their energy directly from the wholesale market.
- The fleet of 5 vehicles operate from 8am to 7pm Monday to Saturday and are parked up and available to charge the rest of the time
- Vehicle batteries are 76kWh
- Each vehicle drives on average 50km per day with an efficiency of 0.7kWh/km
- The supermarket installs 5 x 22kW chargers
- Smart-charging is enabled such that charging occurs at times when energy costs are lowest
- The supermarket is in Sydney and connected tonetwork on EA305 network tariff. It's also exposed to the NEM NSW Spot price for wholesale energy
- Baseline peak demand for the supermarket is 108kW and there's a max site capacity of 150kW, so a little bit of headroom.
A summary of the simulation output is provided below. This is for a 12 month period.
Despite adding ~50MWh of energy consumption to the site with the additional charging requirements, under scenario 2 there is no increase in the site's peak energy demand at all. It remains steady at 108kW.
In scenario 2 the behaviour of the EV chargers is highly consistent, responding to the structure of both the retail supply contract and network tariff.
In scenario 3 where the site is directly exposed to the NSW wholesale market there's much more variability to the charging behaviour is it looks to charge during cheapest trading intervals in the market. The site regularly hits the 150kW site import limit.
So in this case there doesn't look to be a problem for the existing grid connection to support the shift to electrification of the "last mile" fleet.
How would the addition of on-site solar, or V2G, or a stationary battery or a larger fleet, or different vehicle specs change the picture? All good questions and all answered by Gridcog.